"I had just chapped off the motorway and was chapping on by like a Reet Jackie Chapper, when some Jackie (Chapper) nearly chapped into me. I swerved and chapped the lamp-post and chapped myself on the steering wheel."
"Ha ha! Chap!"

A physical and public humiliation defined by a light tap to the back of the neck originating at Arvin High School. A successful chap is characterized by a faint, but very distinguishable smacking sound, followed by laughter among those present.

It may also be used to describe an object that is sub-par, un-cool, stupid, or of poor quality.